Water ingress into fenestration units, which include both doors and windows, is one consideration in product design, construction, and installation. For example, in order to reduce the likelihood of moisture ingress into a dwelling or other structure, door and window assemblies include sealing systems (e.g., gaskets, flanges, and the like) between a unit's frame and panel(s). As might be expected, moisture intrusion is more problematic in situations where there is increased atmospheric moisture and pressure (e.g., as is often the case near oceans or during rain storms).